1. Field of the Invention
The present invention is directed to valves for controlling the flow of either fluids or gases. In particular, the present invention is directed to valves incorporating electroviscous and electro-rheological fluids which are used to control the flow of any fluids, including liquids, gases or slurries.
2. Description of the Prior Art
The present invention is directed to valves which employ electro-rheological fluids that are utilized to control the flow of fluids. In U.S. Pat. No. 4,930,463, electro-rheological valves were utilized in order to control the flow of hydraulic fluid or oil out of a valve controller chamber. The present application illustrates how electro-rheological valves can be universally utilized to control the flow of any fluid, such as gas, water, oil, hydraulic fluid, liquid chemicals, and slurries, between two points along a conduit.
It has been recognized for several decades that certain fluids response to the influence of an electric potential by evidencing a rapid and pronounced increase in viscosity and an increased resistance to shear. Such electro-rheological or electroviscous fluids comprise slurries of finely divided hydrophilic solids in hydrophobic liquids. In the absence of an electric field, these fluids behave in a Newtonian fashion, but when an electric field is applied, the fluids become proportionately more viscous as the potential of the electric field increases. In strong electric fields, these fluids can thicken into a solid. The electro-rheological phenomenon reverses when the electric potential is removed, and the material returns to its fluid state. Electro-rheological fluids change their characteristics very rapidly when electric fields are applied or released, with typical response times being on the order of one millisecond. The ability of electro-rheological fluids to respond rapidly to electrical signals makes them well suited as elements in mechanical devices. Patents directed to compositions of electro-rheological fluids include U.S. Pat. Nos. 3,367,872, 3,047,507 and 4,033,892. Electro-rheological fluids have been extensively used in clutches as disclosed, for example, in U.S. Pat. Nos. 4,444,298 and 4,493,615, and more recently in shock absorbers and hydraulic applications.
Until recently, the practical application of electro-rheological fluids was limited to low temperature environments due to the previously required presence of water in the electro-rheological fluid. In a high temperature environment, the water in the fluid would vaporize and lead to corrosion. This strictly limited the use of electro-rheological fluids away from high temperature applications on or near gasoline and diesel powered automobile and truck engines and the like. Recently, the temperature problem has been minimized with advances in electro-rheological fluid technology such as those disclosed in U.S. Pat. Nos. 4,744,914 and 4,772,407. Electro-rheological devices, because of their special nature, offer numerous advantages over mechanical valve devices incorporating hydraulic, solenoid and cam operated action, such as that utilized in standard valving.
In view of the above, it would be desirable to provide novel valves incorporating electro-rheological fluids which can be used to control the flow of liquids, gases or slurries in a variety of applications.
It would further be desirable to provide an electro-rheological valve having novel electrode configurations situated within the valve itself which facilitate compactness, control, and replaceability.
It is still a further object of the present invention to provide a dual-sided electro-rheological valve which can be utilized to control fluid flow through a system.
A further object of the present invention is to provide an electro-rheological valve mechanism to facilitate control of fluid flow through a system that is compatible with computers or microprocessors.
Another object of the invention is to provide an electro-rheological valve mechanism which employs a microprocessor to control the appropriate electrodes so as to employ the pressure of the fluid being manipulated by the valve mechanism to supply the actuating force to open and close the appropriate valves.
A further object of the invention is to provide an electro-rheological valve mechanism which is self-contained and which can easily be removed and replaced as a single unit.
It is another object of the invention to provide electro-rheological needle valves which have numerous applications, including controlling dampening in conventional oil-filled shock absorbers.
A still further object of the invention is to provide novel electro-rheological valves which can be locked and controlled in open, closed or intermediate positions.